Solved The Serial number: the carousel of numbers

[vince66]

As you well know the so called serial number of a device should be the code that univocally identify it, and correlated to some features like manufacturer, model (?), date manufacturing, etc...

Sometimes it happens that the model of the device as shown on its case is not correlated (or better completely scorrelated) with the serial number that directs to another model.

Sometimes only the assistence centres have (hidden) corrispondence tables to identify the product.

Technically speaking this is tedious and involves confusion.

Commercial stratagems ? or what else ?

Do you know more about ?

 

[ralphbsz]

It's complicated. No, it is not a commercial stratagem. It is actually technically a very complex problem, and you have barely scratched the surface.

On a networking device: Should the serial number be correlated with the MAC address? Should it be identical? It can't be, since the MAC address can be changed in software.

Now a disk drive. A SAS disk has four serial numbers: The one of the physical disk device, one each for both SAS ports, and one for the logical unit (the entity that holds data). Which serial number would you like? They can not be identical. Most manufacturers are pretty sensible about that, and use four consecutive numbers.

You do know that in addition to serial numbers, most devices also have a WWN = world wide unique name? For example, the one for my backup disk drive is 5000c500a44a8bcf (they are binary numbers, traditionally printed in hex). There are various ranges of WWNs, one of which happens to be NAA (and I've forgotten what the others are).

Next question: Part of the identity of the device is its revision level. For example, a disk drive might be manufacturer = Seagate, model = ST1234NM567, serial number ZDZ0BW5E, and software revision SBK2. Now you download a firmware upgrade, and it becomes SBK3. Is it still the same drive or not? Depends on which question you are asking.

Oh, and for fun: The serial number example and WWN example I gave above correspond to each other. A real expert would be able to transcode them into each other.